Hovering mouse over an item should "lock" that slot

[SHADOW13]

When hovering mouse pointer, ie. want to Ctrl/Shift-click it - the slot should be locked, nothing else should be taking that slot
If slot is emptied by something else (like bots) then nothing should be put into that slot until I move mouse away

This is to prevent misclicks, busy places (like cargo hubs) have items arriving and going very quickly, ctrl/shift-clicking items often sends wrong item to the orbit because of that